Model aircraft wing construction



Feb. v1, 1966 L. v. HARRISON MODEL AIRCRAFT WING CONSTRUCTION Filed Nov.26, 1963 INVENTORI LAWRENCE v. HARRISON Maw/ 14 AHy's.

United States Patent 3,232,002 MODEL AIRCRAFT WING CONSTRUCTION LawrenceV. Harrison, Portage la Prairie, Manitoba, Canada (P20. Box 1291,Sackville, New Brunswick, Canada) Filed Nov. 26-, 1963, SenNo. 326,133 1Claim. (CI; 46-78) My invention relates to new and useful improvementsin model manufacture; particularly model aircraft;

Conventional model aircraft, particularly the wings thereof, include afront edge and a trailing edge with a plurality of wooden ribs securedtherebetween together with a plurality of wooden spars extendinglengthwise of the wing all of which are secured together by adhesive.

However, it will be appreciated that these first steps in constructionare extremely tedious, time consuming, and require considerable skill inorder to obtain a finished product which is without distortion andoffers accurate airfoil characteristics.

While it is known also that some wings are preformed from solid woodsuch as balsa, nevertheless these are unsatisfactory due to the weightfactor.

I have overcome these disadvantages by providing a main supportingstructural element formed from a foamed plastic such as polystyrene orsimilar solidified foamed plastic, known under the trade name Styrofoam,which possesses the necessary strength when braced with wood yet isrelatively light in weight having a relatively low density per cubicinch. Furthermore such foamed solid plastics are readily worked so thatcomponents can be attached or recessed within the foamed plastic withthe minimum of dexterity being required.

The principal object and essence of my invention is therefore to providepreformed main supporting struc tural elements for aircraft and the likewhich are readily adapted for further processing either as scale modelor a flying model.

Yet another object of my invention is to provide a device of thecharacter herewithin described which eliminates the first stages ofmodel aircraft construction, therefore minimizing the possibility ofbasic constructional errors occurring.

A yet further object of my invention is to provide a device of thecharacter herewithin described which enables one relatively unskilled inthe art to produce and finish from preformed elements an accurate scalemodel or a model capable of efficient flight.

A still further object of my invention is to provide a device of thecharacter herewithin described which is eminently suitable for useparticularly with model aircraft designed to fly under motor drivenpower.

A still further object of the invention is to provide a device of thecharacter herewithin described which is simple in construction,economical in manufacture, and otherwise well suited to the purpose forwhich it is designed.

With the foregoing objects in view, and such other objects andadvantages as will become apparent to those skilled in the art to whichthis invention relates as this specification proceeds, my inventionconsists essentially in the arrangement and construction of parts all ashereinafter more particularly described, reference being had to theaccompanying drawing in which:

The single drawing figure is a fragmentary isometric sectional view of amodel aircraft wing constructed in accordance with the invention. 7

To date the use of foamed plastic or similar foamed solids in the fieldof model aircraft production has been simply with an aim to present atotally prefabricated craft either completely assembled or in parts suchthat these various foamed plastic parts are joined by wood. It

3,232,092 Patented Feb. I966 ice will be evident that the use of wood isnot as a superstructure but simply as joining elements which enablesmanufactures to kit otherwise cumbersome models. Also noteworthy is thatthe foamed plastic is pre-finished. Hence the use of plastic has beenlimited to rather small craft which prove either weighty or weak incharacteristics. The present methods therefore prove not versatileenough to encompass the diversified fields in model craft building andflying.

In improving upon the above method, my arrangementenables one toconstruct a rigid, lightweight model of both large span and area whichcan withstand both the vibrations of the larger engines and the rigorsand stress involved in competition flying in the various events, as incontrol line flying.

Furthermore, the combination of wood and foamed plastic is not anarbitrary combination (as is the case with the present mode which simplyuses wood as a joiner), but is rather one in which each materialsubstantiates the other, thereby making the best possible use of thecharacteristics of each.

The foam plastic, since it is presented in a workable state, permits thefinishing to be left to the discretion of the builder with a view to themultiplicity of characteristics which might be desired.

Referring now to the accompanying drawing in detail, the model aircraftwing constructed in accordance with the invention is designatedgenerally by the reference numeral 10. The same comprises a wing body 11of low density, homogeneous solidified foam plastic material, the bodyhaving an airfoil cross-section with an upper airfoil surface 12 and alower airfoil surface 13 terminating at a flat vertical front edge 14and a flat vertical rear edge 15.

The wing body 11 is provided with a plurality of aligned rectangularapertures 16 open at the upper and lower surfaces 12, 13 of the wingbody, these apertures defining within the wing body mutuallyintersecting sets of longitudinal and transverse wing body members, asexemplified by the longitudinal body members 11a, 11b, 11c and thetransverse body members 110..

A wooden leading edge member 17 of a substantially semi-circularcross-section is secured by its flat vertical rear edge to the flatvertical front edge 14 of the wing body 11, the rear edge of the member17 being contiguous with the body edge 14 so that the leading edgemember 17 smoothly matches the airfoil contour of the wing. Similarly, aWooden trailing edge member 18 of a substantially triangularcross-section has a flat vertical front edge which is contiguous withand secured to the flat vertical rear edge 15 of the wing body. Securingof the members 17 and 18 to the wing body 11 may be effected in anysuitable manner, as by adhesive.

Formation of the apertures 16 in the wing body lends a character ofexceptional lightness thereto, yet adequate reinforcement is afforded,particularly for the leading longitudinal wing body member 11a and thetrailing longitudinal member He by the wooden leading and trailing edgemembers 17 and 18, respectively.

The members 17 and 18 are preferably made of balsa wood, although other'woods such as pine or cedar, for example, may be employed.

It will be understood that while reference has been made only to a wing,the same construction is also applicable to ailerons, elevators,rudders, and the like.

While in the foregoing there has been described and shown the preferredembodiment of the invention, various modifications may become apparentto those skilled in the art to which the invention relates. Accordingly,it is not desired to limit the invention to this disclosure and variousmodifications and equivalents may be resorted to, falling within thespirit and scope of the invention as claimed.

What I claim as my invention is:

In a model aircraft wing, the combination of a wing body of low densityhomogeneous solidified plastic foam material, said wing body having anairfoil cross-section with upper and lower air-foil surfaces terminatingat a flat vertical front edge and a flat vertical rear edge, said wingbody being provided with a plurality of aligned rectangular aperturesopen at the upper and lower surfaces of the body and defining within thewing body mutually intersecting sets of longitudinal and transverse wingbody members, a wooden leading edge member of a substantiallysemi-circular cross-section having a fiat vertical rear edge contiguouswith and secured to said flat vertical front edge of said wing body, anda Wooden trailing edge member of a substantially triangularcross-section having a fiat vertical front edge contiguous with andsecured to said fiat vertical rear edge of said wing body, saidlongitudinal and transverse wing body members including a ReferencesCited by the Examiner UNITED STATES PATENTS 2,230,393 2/1941 Thomson.2,767,436 10/1956 Noland et al. 3,063,191 11/1962 Main 4679 OTHERREFERENCES Pelaspan Expandable Polystyrene, Catalog 170-90, Dow ChemicalCo., February 1958, page 31.

Sketchbook, American Modeler, vol. 57, No. 6, March 15 1962, page 40relied on.

RICHARD C. PINKHAM, Primary Examiner.

